4. Statistics show that from 2017 to 2018, unemployment decreased while inflation also decreased.Which of the following is a valid reason behind these changes? Aggregate supply curve shifted to the right, which caused the price level to decrease and national output to increase Aggregate supply curve shifted to the left, which caused the price level to increase and national output to decrease Aggregate demand curve shifted to the right, which caused the price level and national output to increase Aggregate demand curve shifted to the left, which caused the price level and national output to decrease 5. After graduating from high school, Individual K decided to enroll in a four-year university program rather than accept a job which offers $13,000 a year.If the annual tuition fee is $5,600, what is Individual K's annual opportunity cost for attending university? $6,400 $11,200 $18,600 $26,000 6. Person B decides to get tested for COVID-19 based on mild symptoms that they are experiencing.In this scenario, a Type I error would occur if.. Person B receives a negative test result stating that they do not have COVID-19, but they actually do Person B receives a positive test result stating that they do have COVID-19, but they actually don't All of the options are correct None of the options are correct